Previously, Strategic Missile Forces (RSVN) commander Sergei Karakayev said Russia would deploy such a weapon only in 2015.

"According to the latest information, it will be accepted into service in 2014; the new weapon is part of a response program to the US ballistic missile defence programme," the source said, without naming the new system.

The Strategic Missile Forces test−fired a prototype of the new weapon in October from the Kapustin Yar test range, he said.

"This was a test launch as part of combined state trials," he said, adding the weapon will be formally accepted only after completion of those trials.

The new weapon will be primarily based on mobile launchers, he said.

"So far there has been no decision on whether to base them in silos," he added.

The missile will have intercontinental range, or more than 5,500 km, he said.